MM-55320 - Limit length of browser user agent version; ratelimit the /sessions endpoint (#25900)

* add ratelimit to /sessions; cap userAgent version length; tests

* add MaxSessionsLimit; remove oldest session first; tests

* can't use slices in 1.20; improve test

* nits

* add GetLRUSessions; move limiting to CreateSession; remove rate limiting

* use queryBuilder

* mysql needs a limit when using offset

* update i18n

* refactor into limitNumberOfSessions; protect createSessionForUserAccessToken

* add comment to GetLRUSessions

* add limit to oauth path; PR comments

server/channels/store/retrylayer/retrylayer.go

@@ -9864,6 +9864,27 @@ func (s *RetryLayerSessionStore) Get(c request.CTX, sessionIDOrToken string) (*m
 
 }
 
+func (s *RetryLayerSessionStore) GetLRUSessions(c request.CTX, userID string, limit uint64, offset uint64) ([]*model.Session, error) {
+
+	tries := 0
+	for {
+		result, err := s.SessionStore.GetLRUSessions(c, userID, limit, offset)
+		if err == nil {
+			return result, nil
+		}
+		if !isRepeatableError(err) {
+			return result, err
+		}
+		tries++
+		if tries >= 3 {
+			err = errors.Wrap(err, "giving up after 3 consecutive repeatable transaction failures")
+			return result, err
+		}
+		timepkg.Sleep(100 * timepkg.Millisecond)
+	}
+
+}
+
 func (s *RetryLayerSessionStore) GetSessions(c request.CTX, userID string) ([]*model.Session, error) {
 
 	tries := 0